1. Field of the invention
The present invention relates to a device for gravimetric metering and pneumatic suction conveying of fluidizable bulk materials.
2. The Prior Art
The metering and pneumatic conveying of the metered quantities of fluidizable bulk materials is fundamentally known. The materials can be conveyed from a storage tank into a receiving vessel by means of pressure conveying or by means of suction conveying. DE 4,109,960 A1, in column 1, second paragraph, mentions the advantages of suction conveying over pressure conveying and describes an installation for pneumatic suction conveying in which measures are taken in order to minimize the risk of blockage.
Another problem of suction conveying is the metering accuracy of the bulk material which is conveyed. In the past, volumetric metering of the bulk material has been known for suction conveying. Due to the changing subatmospheric pressures in the receiving vessel and therefore in the conveying line, this method is unsuitable for accurate metering of the bulk material. For this reason, suction conveying has in the past been unsuitable in particular for modern production installations in which it is necessary to meter changing bulk materials with a high level of accuracy.